this one from eeggs.com
Doctor Who: Series 3 Box Set - Dont Blink...
1) Insert Disc 4 (Which Includes BLINK) into the DVD Player
2) Select Scene Selection for the episode called Blink
3) Highlight Scene 9 which is called "Keep Looking"
4) Press UP
5) The Episode name should now be highlighted.
6) Hit Enter and a familiar Easter Egg should appear...Is he trying to talk to me?

so is this one

Doctor Who - The Movie - Hidden Tribute
When the DVD menu appears press left on the 'Play Movie' symbol, this will highlight the 'DOCTOR WHO' symbol then press enter on your DVD controller.
This will show a tribute to the Late Jon Pertwee (Third Doctor 1919-1996) this was originally shown after the Movie was first broadcast in the UK.
This is a nice touch and a cool tribute to a great actor and a even greater Doctor